What does "collodion" mean?

Collodion: A solution of pyroxylin (soluble gun cotton) in ether containing a varying proportion of alcohol. It is strongly adhesive, and is used by surgeons as a containing for wounds; but its chief application is as a vehicle for the sensitive film in photography. Collodion process (Photog.), a process in which a film of sensitized collodion is used in preparing the plate for taking a picture. -- Styptic collodion, collodion containing an astringent, as tannin.